Rotary tool holder

ABSTRACT

A tool holder for releasably coupling a bit with a non-circular outer connector surface to a rotary driver. The tool holder includes a socket and a retaining mechanism coupled to the socket and operable in a retaining mode and a released mode. The socket includes a forward end with an opening extending rearwardly from the forward end. The opening also includes a non-circular cross-section adapted to receive the outer connector surface of the bit to couple the bit for rotation with the socket. The retaining mechanism is adapted to permit disposable of the bit into an operative position within the opening and to prevent axial movement of the bit out of its operative position when the retaining mechanism is in its retaining mode. The retaining mechanism is further adapted to permit axial displacement of the bit out of its operative position when the retaining mechanism is in its released mode. The retaining mechanism includes a sleeve coupled to the socket for displacement toward the forward end of the socket from a locked position to an unlocked position thereby moving the retaining mechanism from its retaining mode into its released mode. The retaining mechanism also includes a spring biasing the sleeve into its locked position.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates generally to a tool holder for use with arotary driver such as a drill and, more particularly, to an improvedretaining mechanism for such a tool holder.

2. Discussion

Tool holders for rotary drivers such as drills are generally known inthe art. Some tool holders directly couple bits, such as drilling bitsor screw driving bits, to the rotary driver. Other holders couplereversible tools to the driver. U.S. Pat. No. 5,779,404 to Jore entitled“Reversible Drill/Driver Tool” is representative of the latter holders.

Tool holders generally include a drive body having a shank at one endand a socket at the other. The socket is configured to accommodate thebit and a retaining mechanism is coupled to the socket to releasablycouple the bit or bit holder to the socket for rotation with the toolholder. Prior art retaining mechanisms commonly include a retaining ballor spring that protrudes into the socket to couple the bit or bit holderto the socket. A sleeve or collar is axially movable along the socketbetween a locked position wherein the ball is maintained in its engagedposition and an unlocked position wherein an annular recess in thesleeve or collar is aligned with the ball or spring to allow the ball orspring to move to a disengaged position and permit removal of the bit orbit holder from the socket.

One of the disadvantages of many prior art tool holders is that thesleeve or collar must be in its unlocked position to permit the bit tobe moved into the socket. Accordingly, when an operator desires tocouple the bit to the tool holder, the operator must first determinewhether the sleeve is in its locked or unlocked position. If the sleeveis in its locked position, the operator must move the sleeve to itsunlocked position prior to disposing the bit holder within the socket.Finally, after positioning the bit holder in the socket, the operatormust move the sleeve to its locked position.

Further deficiencies in the prior art include retaining mechanismconfigurations that require two distinct movements to remove the bitholder from the socket. For example, some retaining mechanisms requirerearward movement of the sleeve into its unlocked position followed byforward displacement of the bit holder away from the socket toeffectuate removal. This bi-directional displacement sequence isundesirably inefficient.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a tool holder havinga retaining mechanism that permits a bit to be disposed within andcoupled to the socket when the retaining mechanism sleeve is in itslocked position.

A further object of the present invention is to provide a retainingmechanism having a sleeve and a spring that normally biases the sleeveinto its locked position thereby effectively retaining a bit in drivingengagement with the socket when the bit is disposed therein.

Yet another object of the present invention is to provide a retainingmechanism having a key that is disposed within a slot in the socket formovement between an engaged position and first and second disengagedpositions. The key is in operative engagement with a retaining sleevethat is biased to its normal locked position yet moveable into anunlocked position. When the sleeve is in either its locked or unlockedpositions, the sleeve is configured to permit the key to move to itsfirst disengaged position to allow insertion of a bit within the socket.Further, the sleeve prevents movement of the key to its seconddisengaged position when the sleeve is in its normally locked positionthereby retaining the bit holder to the socket.

A still further object of the present invention is to provide aretaining mechanism wherein the sleeve is rearwardly biased into itslocked position such that forward movement of the sleeve against thebias places the sleeve in its unlocked position and allows the operatorto displace the sleeve and the bit in the same axial direction andremove the bit from the socket in an efficient, and preferablyone-handed, operation.

In view of the above, the present invention includes a tool holder forreleasably coupling a bit with a non-circular outer connector surface toa rotary driver. The tool holder includes a socket and a retainingmechanism coupled to the socket and operable in a retaining mode and areleased mode. The socket includes a forward end with an openingextending rearwardly from the forward end. The opening also includes anon-circular cross-section adapted to receive the outer connectorsurface of the bit to couple the bit for rotation with the socket. Theretaining mechanism is adapted to permit disposable of the bit into anoperative position within the opening and to prevent axial movement ofthe bit out of its operative position when the retaining mechanism is inits retaining mode. The retaining mechanism is further adapted to permitaxial displacement of the bit out of its operative position when theretaining mechanism is in its released mode. The retaining mechanismincludes a sleeve coupled to the socket for displacement toward theforward end of the socket from a locked position to an unlocked positionthereby moving the retaining mechanism from its retaining mode into itsreleased mode. The retaining mechanism also includes a spring biasingthe sleeve into its locked position.

Further scope of applicability of the present invention will becomeapparent from the detailed description given hereinafter. It should beunderstood however that the detailed description and specific examples,while indicating preferred embodiments of the invention are intended forpurposes of illustration only, since various changes and modificationswithin the spirit and scope of the invention will become apparent tothose skilled in the art from the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thefollowing detailed description and the accompanying drawings wherein:

FIG. 1 is a side elevational view of a rotatable tool with a tool holderaccording to the present invention;

FIG. 2 is a sectional view taken along the line 2—2 shown in FIG. 1 andillustrating the retaining mechanism in its retaining mode, the sleevein its locked position, and the key in its engaged position;

FIG. 3 is a sectional view taken along the same line as FIG. 2 with thesleeve illustrated in its locked position and the key displaced into itsfirst disengaged position by insertion of the bit holder;

FIG. 4 is a sectional view taken along the same line as FIGS. 2 and 3illustrating the retaining mechanism in its released mode, the sleeve inits unlocked position, and the key displaced into its second disengagedposition by removal of the bit holder;

FIG. 5 is a longitudinal or axial sectional view of the sleeve;

FIG. 6 is a side elevational view of the key;

FIG. 7 is a side elevational view of a tool holder according to anotherembodiment of the present invention and illustrates a drill bit about tobe inserted into the tool holder; and

FIG. 8 is a sectional view taken generally along the line 8—8 of FIG. 7illustrating the drill bit fully inserted into the tool holder.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to FIGS. 1 and 2, a rotatable tool 10 is generallyillustrated to include a tool holder 12 and a bit assembly 14. The toolholder 12 includes a retaining mechanism 16, that is normally biasedinto a retaining mode (FIG. 2) to prevent axial removal of the bitassembly 14 from the tool holder 12 but allows insertion of the bitassembly 14 therewithin. The retaining mechanism 16 is movable into areleased mode (FIG. 4) wherein the bit assembly 14 is removable from theholder body.

The tool holder 12 includes a shank 18 integral with and extendingrearwardly from a socket 20. The exterior of the shank 18 is preferablyhex-shaped (FIG. 1) for coupling to a drive mechanism such as the chuckof a rotary drill. The tool holder 12 includes a passage 22 (FIG. 3)extending through the socket 20 and shank 18. The passage 22 is defined,in part, by a hex-shaped opening 26 extending rearwardly from a firstend 28 of socket 20. Further, a reduced diameter bore 30 communicateswith opening 26 and an even smaller axial passage 32 formed in shank 18.The decrease in size between the opening 26 and bore 30 defines anannular shoulder 34.

Bit assembly 14 includes first and second bits 50 and 52 secured to abit holder 38. The bit holder 38 includes a middle segment 40 having anouter surface that is configured for driving engagement with hex-shapedopening 26. Middle segment 40 is flanked by first and second outersections 42 and 44 that are preferably cylindrical in shape. Each of thefirst and second outer sections 42 and 44 include circumferentialgrooves 46 that are positioned for engagement with the retainingmechanism 16 as hereinafter described. Thus, the bit holder 38 may bedisposed within the socket 20 such that one of the first and second bits50 and 52 extend from the tool holder for operative engagement with awork piece.

It should be appreciated that while the tool holder 12 of the presentinvention is described with particular reference to the reversible bitassembly 14 in FIGS. 1-6, the tool holder may also be used in a varietyof other tool coupling environments. For example, as is illustrated inFIGS. 7 and 8, an alternative embodiment of the tool holder 212 andretaining mechanism 216 may be used to allow the operator to efficientlyconnect and disconnect any bit or tool to a driver such as a drill. Infact, the tool holder may be used to connect virtually any type ofrotary bit with a hex-shaped shank and a groove in the shank directly toa rotatable driver.

As noted above, the retaining mechanism 16 releasably couples the bitassembly 14 to the tool holder 12 when the retaining mechanism is in itsretaining mode yet allows the operator to remove the bit assembly fromthe tool holder in a smooth and efficient manner. More particularly, thebit assembly 14 is removable from the tool holder 12 through forwardmovement of a retaining mechanism sleeve and corresponding forwardmovement of the bit assembly 14. This coordinated, unidirectionalremoval operation allows the operator to easily remove the bit from thetool holder and, preferably, perform such removal with a single hand.

The retaining mechanism includes a sleeve 60, a spring 61, and a detentmechanism 88. The sleeve 60 is coupled to the outer surface of thesocket 20 for sliding axial movement therealong between its lockedposition (FIGS. 2 and 3) when the retaining mechanism is in itsretaining mode and its unlocked position (FIG. 4) when the retainingmechanism is in its released mode. The spring 61 biases the sleeve 60toward its locked position and therefore the retaining mechanism 16 intoits retaining mode. The detent mechanism includes a key 90 and a detentspring or snap ring 106. The key 90 is disposed for sliding movementbetween an engaged position (FIG. 2) and first and second disengagedpositions (FIGS. 3 and 4, respectively) relative to a key slot 92 (FIG.3) in the socket 20. The detent spring 106 biases the key into itsengaged position.

In general, the configuration of the sleeve 60 and detent mechanism 88provide many of the benefits discussed above. For example, the sleeve isbiased into its locked position wherein the sleeve configuration permitsthe bit assembly to displace the key 90 from its engaged position andinto its first disengaged position (FIG. 3) during insertion of the bitinto its operative position (FIG. 2) within the socket opening 26. Inits locked position, the sleeve also prevents displacement of the key 90from its engaged position to its second disengaged position under forcestending to remove the bit assembly 14 from its operative position.Finally, an operator may displace the sleeve 60 into its unlockedposition (FIG. 4) wherein movement of the bit assembly of the socketopening 26 displaces the key 90 into its second disengaged position.

As is most clearly illustrated in FIG. 5, the sleeve includes a centralshoulder 62 and collars 64 and 66 extending forwardly and rearwardlytherefrom, respectively. The inner surface of the sleeve includes aconstant diameter recess 74 extending from a spring seat 72 defined bycentral shoulder 62 (FIG. 5) to the forward face 76 of the forwardlyextending collar 64. In a similar manner, the inner surface of sleeve 60defines a rear recess 78 extending from shoulder 62 to the terminal end80 of rearwardly extending collar 66. Rear recess 78 includes a conicalsection 82 adjacent central shoulder 62 that is defined by a slantedface 84 radially diverging from shoulder 62. Rear recess 78 alsoincludes a cavity 86 extending from conical section 82 to terminal end80. Finally, as is best illustrated in FIG. 1, the outer surface ofsleeve 60 includes a concave depression 68 extending between knurledsections 70 to facilitate movement of the sleeve from its normal lockedposition to its unlocked position such as through manipulation by theoperator's thumb.

As shown in FIG. 6, the key 90 of detent mechanism 88 includes a bottomface 94 that is slidable along a slanted bearing surface 96 (FIG. 3)adjacent the slot 92. The key 90 also includes a forward face 98, a topface 100, a slanted face 102, and a spring recess 104 between theslanted face 102 and top face 100. The detent spring 106 (FIG. 2) isdisposed within spring recess 104 and a circumferential snap groove 108(FIG. 4) in the outer surface of the socket 20.

It should be noted for completeness that the tool holder 12 furtherincludes rear and front press collars 110 and 112, respectively, (FIG.4) for securing the sleeve for sliding movement along the outer surfaceof the socket.

With the above description of the structure of the tool holder in mind,the operation thereof will now be described in greater detail withrespect to FIGS. 2, 3, and 4. As noted above, the spring 61 normallybiases the sleeve into its locked position and the spring 106 normallybiases the key 90 into its engaged position (FIG. 2). Insertion of thebit holder 38 is permitted when the sleeve 60 is in its locked orunlocked position. More particularly, as is best illustrated in FIG. 3,during axial insertion of the bit holder 38 in the direction of arrow114 and into the hex-shaped opening 26, a displacing face 116 of the bitholder engages the forward face 98 of the key 90 and slidably displacesthe key in the direction of arrow 118 and along the socket bearingsurface 96 into its first disengaged position.

When the bit holder 38 is fully inserted into the socket 20, i.e., thebit assembly 14 is in its operative position relative to the tool holder12, the detent spring 106 biases the key 90 into engagement with one ofthe circumferential grooves 46 formed on the outer surface of the bitholder. In this position, if the operator or drilling forces act in thedirection opposite arrow 114, the attempted removal of the bit assembly14 tends to displace the key 90 in a direction indicated by arrow 120(FIG. 2). Such key displacement is prevented through engagement of thetop key face 100 (FIG. 6) with the slanted face 84 of the sleeve 60(FIG. 2) and the key retains the bit holder 38 in the socket 20. If theoperator desires to remove the bit holder, the operator simply displacesthe sleeve in a forward direction against the bias of the spring 61thereby placing the cavity 86 in operative alignment with the key 90(FIG. 4). The key 90 is then allowed to move in the direction of arrow120 into its second disengaged position under the urging of the bitholder 38, as illustrated in FIG. 4, thereby allowing removal of the bitholder.

One skilled in the art will appreciate that the reversible tool andretaining mechanism of the present invention provides many benefits overthe prior art. These benefits include allowing the releasable couplingof the bit assembly 14 to the tool holder 12 when the sleeve 60 is ineither its locked or unlocked positions. Moreover, the biasing of thesleeve 60 into its locked position ensures that the retaining mechanism16 is not inadvertently left in an unlocked position where the bitholder may be easily removed from the drive body. Additionally, theretaining mechanism is configured such that the key 90 is movable fromits engaged position to its first disengaged position through slidingmovement in a first direction indicated by arrow 118 and is movable fromits engaged position to its second disengaged position in a seconddirection indicated by arrow 120 that is approximately orthogonal to thefirst direction 118.

Further, the forward movement of the sleeve 60 from its locked positionto its unlocked position allows the key 90 to be displaced to its seconddisengaged position and the operator to efficiently remove the bitassembly 16 from the socket 20 through coordinated, and preferablyone-handed, axial movement of the sleeve 60 and the bit assembly 14.More particularly, many prior art tool holders require rearward movementof the retaining sleeve to place the sleeve in its unlocked position.The bit assembly must then be moved in the opposite direction todisassemble the tool. Conversely, the tool holder of the presentinvention is configured such that the sleeve and bit assembly are eachmoved in the same forward axial direction to place the sleeve in itsunlocked position and to remove the bit assembly from the socket. Thisunidirectional movement provides more efficient and coordinatedoperation of the tool.

Turning now to FIGS. 7 and 8 wherein the tool holder of the presentinvention, including the retaining mechanism thereof, is shownincorporated into a quick-acting tool bit holder 212 for releasablycoupling a bit 214 to the tool holder socket 220. More particularly, asillustrated in FIG. 7, the tool holder 212 is adapted to releasablycouple the bit 214 to a rotary driver 217 and to achieve all of thebenefits recited above. In a manner consistent with the description ofthe retaining mechanism provided above with reference to FIGS. 1-6, theretaining mechanism 216 illustrated in FIG. 8 includes a sleeve 260,spring 261, and detent mechanism 288 which is illustrated in its engagedmode to retain the bit 214 within a passage 222 defined by socket 220.The detent mechanism 288 includes a key 290 that engages acircumferential groove 246 formed in hex shank 240 of bit 214. The toolholder 212 includes a shank 218 that is connectable to the rotary driver217. From the above description referencing FIGS. 7 and 8 as well as thedisclosure relating to FIGS. 1-6, it should be appreciated that theretaining mechanism of the present invention may be used in a variety ofenvironments to provide the benefits discussed herein.

The invention being thus described, it will be obvious that the same maybe varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be within the knowledge of one skilled in the artare intended to be included within the scope of the following claims.

What is claimed is:
 1. A tool holder for releasably coupling a bit witha non-circular outer connector surface to a rotary driver, comprising: asocket having a forward end and an opening extending rearwardly fromsaid forward end, said opening having a non-circular cross sectionadapted to receive the outer connector surface of the bit to couple thebit for rotation with the socket; a retaining mechanism coupled to saidsocket and operable in a retaining mode and a released mode, saidretaining mechanism adapted to permit disposal of the bit into anoperative position within the opening and to prevent axial displacementof the bit out of its operative position when the retaining mechanism isin its retaining mode, said retaining mechanism further adapted topermit axial displacement of the bit out of its operative position whenthe retaining mechanism is in its released mode, said retainingmechanism including a sleeve and a spring, said sleeve coupled to saidsocket for displacement toward said forward end of said socket from alocked position to an unlocked position to move said retaining mechanismfrom said retaining mode to said released mode, said spring biasing saidsleeve into its locked position; and wherein said retaining mechanismincludes a detent mechanism movable between an engaged position andfirst and second disengaged positions, wherein said socket includes aslot communicating with said opening, wherein said detent mechanism isadapted to extend through said slot and into said opening to engage thebit and prevent axial removal of the bit from its operative positionwhen the detent mechanism is in its engaged position.
 2. The tool holderof claim 1 wherein said detent mechanism is adapted to permit insertionof the bit into the opening when the detent mechanism is in its firstdisengaged position, wherein said detent mechanism is further adapted topermit removal of the bit from the opening when the detent mechanism isin its second disengaged position, wherein said detent mechanism isdisplaceable from its engaged position to its first disengaged positionwhen the retaining mechanism is in its retaining mode, wherein saidsleeve prevents displacement of said detent mechanism from its engagedposition to its second disengaged position when said retaining mechanismis in said retaining mode, and wherein said detent mechanism isdisplaceable from its engaged position to its second disengaged positionwhen the retaining mechanism is in its released mode.
 3. The tool holderof claim 2 wherein said socket includes a slanted bearing surfaceextending rearwardly from said slot, wherein said detent mechanismincludes a key disposed in said slot, said key positioned to engage thebit during insertion of the bit into said opening and to be displaced bythe bit to slide along said bearing surface from the engaged position tothe first disengaged position.
 4. The tool holder of claim 2 whereinsaid detent mechanism is movable in a first direction from its engagedposition to its first disengaged position and in a second directiongenerally orthogonal to said first direction from its engaged positionto its second disengaged position.
 5. A tool holder for releasablycoupling a bit with a non-circular outer connector surface to a rotarydriver, comprising: a socket having a forward end and an openingextending rearwardly from said forward end, said opening having anon-circular cross section adapted to receive the outer connectorsurface of the bit to couple the bit for rotation with the socket; asleeve displaceable axially along said socket between a locked positionand an unlocked position; a spring biasing said sleeve toward its lockedposition; a detent mechanism having a detent spring, said detentmechanism extending into said opening and adapted to engage the bit andprevent axial removal of the bit from the opening when said detentmechanism is in an engaged position; said detent mechanism being movablebetween its engaged position to first and second disengaged positions,said sleeve preventing movement of said detent mechanism from itsengaged position into its second disengaged position while permittingmovement of said detent mechanism from its engaged position into itsfirst disengaged position when said sleeve is in its locked position,said sleeve permitting movement of said detent mechanism from itsengaged position to its second disengaged position when said sleeve isin its unlocked position.
 6. The tool holder of claim 5 wherein saiddetent mechanism includes a key and said socket includes a slotcommunicating with said opening and a slanted surface extendingrearwardly from said slot, and wherein said key slides along saidslanted surface when the detent mechanism is moved from its engagedposition to its first disengaged position.
 7. The tool holder of claim 6wherein said key is displaced away from said slanted surface when thedetent mechanism is moved from its engaged position to its seconddisengaged position.
 8. The tool holder of claim 7 wherein said sleeveincludes a recess having a conical section and a cavity extendingrearwardly from said conical section.
 9. The tool holder of claim 8wherein said conical section includes a slanted face that preventsdisplacement of said key away from said slanted surface when said sleeveis in its locked position.
 10. The tool holder of claim 7 wherein saidcavity is moved into operative engagement with said key when said sleeveis displaced into its unlocked position to accommodate said key whensaid detent mechanism is in its second disengaged position.
 11. The toolholder of claim 5 wherein said sleeve is displaced toward said forwardend of said socket to move said sleeve from its locked position to itsunlocked position.
 12. A rotatable tool comprising: a bit having anon-circular outer connector surface; and a tool holder having a socketand a retaining mechanism, said socket having a forward end and anopening extending rearwardly from said forward end, said opening havinga non-circular cross section, said bit being disposable in an operativeposition within said socket wherein said opening receives said connectorsurface to couple said bit for rotation with said tool socket, saidretaining mechanism including: a detent mechanism movable between anengaged position and first and second disengaged positions, said bitdisplacing said detent mechanism into its first disengaged positionduring insertion of the bit into its operative position, said detentmechanism extending into said opening to engage the bit and preventaxial removal of the bit from the opening when said detent mechanism isin its engaged position and the bit is in its operative position, saidbit displacing said detent mechanism into its second disengaged positionduring removal of the bit from its operative position, said detentmechanism including a spring biasing said detent mechanism into itsengaged position, a sleeve displaceable axially along said socketbetween a locked position and an unlocked position, said sleevepreventing movement of said detent mechanism from its engaged positioninto its second disengaged position while permitting movement of saiddetent mechanism from its engaged position into its first disengagedposition when said sleeve is in said locked position, said sleevepermitting movement of said detent mechanism from its engaged positionto its second disengaged position when said sleeve is in said unlockedposition, and a spring normally biasing said sleeve into said lockedposition.
 13. The rotatable tool of claim 12 wherein said bit is areversible bit assembly including a bit holder, a first bit coupled tosaid bit holder to extend therefrom in a first direction, a second bitcoupled to said bit holder to extend therefrom in a second directionopposite said first direction.
 14. The rotatable tool of claim 12wherein said bit includes a shank having a groove, said detent mechanismengaging said groove when said bit is in its operative position and saiddetent mechanism is in its engaged position.
 15. The rotatable tool ofclaim 12 wherein said sleeve is displaced toward said forward end ofsaid socket to move said sleeve from its locked position to its unlockedposition.